Newtown, Connecticut (CNN) -- In one of the deadliest school shootings in U.S. history, a gunman opened fire Friday in a Connecticut elementary school, killing 26 people, 20 of them children, police said.
The suspected gunman, who was not identified by police, also was killed, apparently by his own hand.
One person was wounded.
The mass shootings occurred in one section of Sandy Hook Elementary School and spanned two classrooms, said Lt. Paul Vance of the Connecticut State Police.
Among the dead were the school's principal and psychologist, according to a parent who was at the school when the incident happened.
Separately, another adult was found dead at a second location in Newtown, Vance said. A law enforcement source with detailed knowledge of the investigation identified that person as Nancy Lanza, the mother of the suspected shooter, who was found dead at her son's home. She was a teacher at Sandy Hook, sources said.
Vance described "a very tragic, tragic scene," noting the carnage first responders witnessed when they arrived.
"I have difficulty putting it into words," Vance told CNN, adding that he has "seen some horrific things, and this is right up there with them."
Police recovered three weapons from the scene: a semi-automatic .223 Bushmaster, a Glock and a Sig Sauer, a source with knowledge of the investigation said. Vance said that the medical examiner will determine the cause of death for the gunman, though he noted that police never discharged their weapons.
Meanwhile, authorities in Hoboken, New Jersey, were questioning a man believed to be the brother of the suspected shooter, two law enforcement sources said.
President Barack Obama addressed the shooting in an emotional statement Friday afternoon, saying, "Our hearts are broken today." Obama, a father to two girls, wiped away tears as he noted the nation has "endured too many of these tragedies in the past few years."
Police and teachers rushed students from the building as police swarmed the area shortly after the first calls came in, around 9:40 a.m. ET. Officials moved students to a nearby firehouse, where parents frantically sought information about their children.
"Why? Why?" one woman wailed as she walked up a wooded roadway leading from the school.
Third-grader Alexis Wasik said police and teachers barged into her classroom and told students to hide in the corner.
"Everybody was crying," she said. "And I just heard the police officers yelling."
Aerial images from CNN affiliate News 12 New Jersey showed police officers armed with rifles following a dog into woods near the school.
Other officers, some in tactical gear, stood around the school with guns drawn, CNN affiliate WFSB reported.
All schools in the city were on lockdown Friday as police assessed the situation, Vance said.
Gov. Dannel Malloy is "horrified" by what happened, a spokesman said. Malloy was meeting with families Friday afternoon, the spokesman said.
Obama ordered flags to half-staff nationwide in honor of the victims.
If the number of fatalities remains at 26, the Newtown shooting would be the second-deadliest school shooting in U.S. history, behind only the 2007 shooting at Virginia Tech that left 32 people dead.
In 1999, at Columbine High School in Littleton, Colorado, two students shot 13 people to death before killing themselves.

Will do. Thanks, friend.

It's unfathomable. I pray we never have something this tragic hit anywhere close to our home.

I really wish people would just stop talking about anything other than the tragedy of the entire situation. It's appalling.

Yeah. Necessary evil for most folks, though. I don't have the cash to pay for the house outright, lol.

...moving right along I got the call today to ask about scheduling preferences for the appraisal. Just waiting now on confirmation! I told them I could be there in 20 minutes to open the lock box and let them in if needed, lol.